Your low voltage is good, transformer good, t-stat good, indoor blower good....
most likely possibilities - bad contactor, or bad outdoor fan, or bad fan capacitor
with the power off the outdoor unit - reach down with a screw driver and see if u can spin the fan blade - if its hard to spin than the bearings went out on your motor and you'll need a new one....I hate to have you check the contactor (main relay) because I don't want you to electric yourself. Probly have to call someone.
If the compressor runs then its your fan....if not than its most likely the fans bad....check the fan like I said, another possibility is a broken t-sat wire to your unit. That would be a possibility if the contactor is good and neither the fan or compressor are working.
Check your breaker box to see if it tripped... if neither fan or compressor are working...if this is the case u might have a shorted compressor